LL-37 vs PNC-27
Human cathelicidin-derived antimicrobial peptide (37 amino acids) that disrupts bacterial membranes at MIC 0.62 μM against S. aureus, neutralizes endotoxin (LPS) to prevent septic shock, and has reached Phase II clinical trials as Ropocamptide for wound healing — achieving 6-fold accelerated healing at 0.5 mg/mL in venous leg ulcers
A cancer-fighting peptide that works like a smart missile—it hunts down and destroys cancer cells by poking holes in them, while leaving your healthy cells completely untouched.
Quick comparison
Dose range
LL-37
1.6–1.6 mg/mL
PNC-27
1–2 mg
Frequency
LL-37
Once daily
PNC-27
Once daily
Administration
LL-37
Topical application (wound healing)
PNC-27
Subcutaneous injection
Cycle length
LL-37
12+ weeks
PNC-27
4-6 weeks
Onset speed
LL-37
Moderate (1-2 weeks)
PNC-27
Rapid (hours to days)
Evidence level
LL-37
Moderate human trials (Phase 1-2)
PNC-27
Strong preclinical (extensive animal studies)
Benefit ratings
Wound Healing
Fighting Infections
Immune Boost
Cancer Cell Selectivity
Rapid Action
Broad Spectrum
Compound specifications
LL-37
Molecular formula
C205H340N60O53
Molecular weight
4,493.26 Da
Half-life
Short systemic half-life (minutes) due to protease susceptibility; local tissue persistence at wound sites is longer due to binding to extracellular matrix components and lipid membranes
Bioavailability
Topical application achieves high local wound-bed concentrations; systemic bioavailability limited by rapid proteolytic degradation and serum protein binding; not intended for oral delivery
CAS number
154947-66-7
PNC-27
Molecular formula
C188H293N53O44S
Molecular weight
4031.73 g/mol
Half-life
2-4 hours (estimated from preclinical data)
Bioavailability
High when injected subcutaneously
CAS number
1159861-00-3
Dosing compared
LL-37
Topical
0.5 mg/mL gel
Twice weekly · 4 weeks
Lowest dose in the LL-37 (ropocamptide) Phase I/IIa venous leg-ulcer trial and the most effective: ~6-fold faster healing and ~68% ulcer-area reduction vs placebo, applied to the wound twice weekly [4].
1.6 mg/mL gel
Twice weekly · 4 weeks
Mid dose in the same trial; ~3-fold improvement and ~50% area reduction vs placebo. The highest tested concentration (3.2 mg/mL) showed no benefit over placebo, so dose escalation above this is not supported [4].
PNC-27
Best suited for
LL-37
Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers
LL-37 is particularly well-suited for individuals focused on treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)
LL-37 is particularly well-suited for individuals focused on immune defense against antibiotic-resistant bacterial infections (mrsa, pseudomonas). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Anti-biofilm strategies for chronic wound infections and medical device-associated infections
LL-37 is particularly well-suited for individuals focused on anti-biofilm strategies for chronic wound infections and medical device-associated infections. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Boosting innate immune defense in immunocompromised or aging individuals
LL-37 is particularly well-suited for individuals focused on boosting innate immune defense in immunocompromised or aging individuals. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
PNC-27
Solid Tumor Research
PNC-27 has shown remarkable results against solid tumors in lab studies. It's been tested against breast, pancreatic, colon, and ovarian cancer cells—and in each case, it killed the cancer cells while the healthy cells next to them stayed perfectly fine. That's the holy grail of cancer research.
Leukemia and Blood Cancer Studies
In studies on acute myeloid leukemia (AML), PNC-27 wiped out cancer cells within just 4 hours. It works on several types of leukemia cells (U937, OCI-AML3, HL-60) by targeting a protein that only shows up on cancer cell surfaces. Normal blood cells? Completely unharmed.
Cancer Stem Cell Targeting
Here's where PNC-27 gets really interesting: it can kill cancer stem cells. These are the sneaky cells that often survive chemo and cause cancer to come back. PNC-27 has shown it can destroy CD44+ colon cancer stem cells, which is a big deal for preventing recurrence.
Drug-Resistant Cancer Research
When cancers stop responding to regular chemotherapy, researchers need new approaches. PNC-27 works through a completely different mechanism than traditional chemo drugs, so it may be effective against cancers that have become resistant to other treatments.
Side effects
LL-37
Common
- Local site irritation
- Transient stinging or burning
- Mild perilesional erythema
- Increased wound exudate
Uncommon
- Allergic contact reaction
Serious
- Hemolytic activity at systemic concentrations
PNC-27
Common
- Injection site redness
- Mild fatigue
- Localized warmth or tenderness
Uncommon
- Headache
- Low-grade fever
Serious
- Allergic reaction
Safety & evidence
LL-37
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
LL-37 is an endogenous cathelicidin antimicrobial peptide naturally produced by immune cells and epithelial tissues, conferring inherent biocompatibility and low toxicity at physiological concentrations. Synthetic LL-37 shows excellent safety in in vitro immune assays and animal models with no hepatotoxicity, nephrotoxicity, or genotoxicity at relevant doses. At elevated concentrations, the cationic amphipathic structure can cause hemolysis and cell membrane damage, but therapeutic doses are far below these thresholds. Injection site reactions are minimal in research applications.
Contraindications
- Known hypersensitivity to cathelicidin peptides or formulation components
- Active hemolytic conditions — LL-37 demonstrates concentration-dependent hemolytic activity
- Pregnancy and breastfeeding — insufficient reproductive safety data from clinical trials
- Severe renal impairment — peptide clearance may be altered
PNC-27
Evidence level
Strong preclinical (extensive animal studies)
FDA status
Research compound
Safety overview
Here's the really cool thing about PNC-27: in all the lab and animal studies so far, it ONLY attacks cancer cells. Normal, healthy cells are completely ignored because they don't have the protein (HDM-2) on their surface that PNC-27 targets. Animal studies using doses up to 40 mg/kg showed tumors shrinking or disappearing with zero damage to normal tissues. That said, it hasn't been tested in human clinical trials yet, so we're still learning.
Contraindications
- Pregnancy or planning to become pregnant
- Currently breastfeeding
- Known allergy to peptide components
- Severe immune system disorders without specialist guidance
Which is right for you?
Choose LL-37 if...
- Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers
- Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)
- Anti-biofilm strategies for chronic wound infections and medical device-associated infections
- Boosting innate immune defense in immunocompromised or aging individuals
Choose PNC-27 if...
- Cancer research protocols
- Oncology support research
- Targeting treatment-resistant cancers
- Cancer stem cell research